East County hit by 700 lightning strikes

Powerful thunderstorms produced about 700 cloud-to-ground lightning strikes Monday in East County and dumped up to two inches of rain in some areas, briefly causing driving to become hazardous on Interstate 8 near the border of San Diego and Imperial counties, says the National Weather Service.

A fresh round of thunderstorms is expected to clobber the county’s mountains and deserts today (Tuesday), followed by isolated boomers on Wednesday.

“We have the combination of monsoon moisture coming up from northwest Mexico and daytime heating that leaders to unstable air, and thunderstorms,” said James Thomas, a weather service forecaster.

Monday’s thunderstorms began booming across East County shortly after noon, spitting lightining across a wide area that included Julian, Santa Ysabel, the Cuyamaca Mountains, Shelter Valley, Campo, Portrero, and Cameron. Forecasters issued a flash flood warning, which proved to be timely. Cameron Corners got two inches of rain, and Shelter Valley, east of Julian, received more than an inch of rain in 15 minutes.

Forecasters closely monitor such convection because lightning can hit the ground and cause wildfires, and it poses a danger to people. On average, says the weather service, lightning kills 40 people and injures 360 in the U.S. each year.

The air around a bolt of lightning can heat up to 50,000 degrees.
Associated Press

The American Red Cross says that if you're caught outside during a lightning storm and cannot reach shelter, you should:

Go to a low-lying, open place away from trees, poles, or metal objects. Make sure the place you pick is not subject to flooding

Be a very small target. Squat low to the ground. Place your hands on your knees with your head between them. Make yourself the smallest target possible

Do not lie flat on the ground--this will make you a larger target

Weather conditions will be far more pleasant in other parts of the county. The weather service says the temperatures at and near the coast will be in the low 70s on Monday and Tuesday, and in the 80s across most inland valleys and foothills. The deserts will be in the upper 90s and low 100s.

Kate Kelly of Detroit, Michigan paddles out through the green tide Saturday in Del Mar.

As we reported over the weekend, there are long, bright lime-colored patches in and near the surf zone along the county's coast, particularly from Solana Beach to La Jolla. Scientists say the county is experiencing a "green tide", which is caused by a large bloom of phytoplankton. It's harmless.